Various earth-boring tools such as rotary drill bits (including roller cone bits and fixed-cutter or drag bits), core bits, eccentric bits, bicenter bits, reamers, and mills are commonly used in forming bore holes or wells in earth formations. Such tools often may include one or more cutting elements on a formation-engaging surface thereof for removing formation material as the earth-boring tool is rotated or otherwise moved within the bore hole.
For example, fixed-cutter bits (often referred to as “drag” bits) have a plurality of cutting elements affixed or otherwise secured to a face (i.e., a formation-engaging surface) of a bit body. FIG. 1 illustrates an example of a conventional cutting element 10. The cutting element 10 includes a layer of superabrasive material 12 (which is often referred to as a “table”), such as mutually bound particles of polycrystalline diamond, formed on and bonded to a supporting substrate 14 of a hard material such as cemented tungsten carbide. The table of superabrasive material 12 includes a front cutting surface 16, a rear face (not shown) abutting the supporting substrate 14, and a peripheral surface 18. As also depicted, it is conventional, although not required, that a chamfer 20 be located between the front cutting surface 16 and the peripheral surface 18. During a drilling operation, a portion of a cutting edge, which is at least partially defined by the peripheral portion of the cutting surface 16, is pressed into the formation. As the earth-boring tool moves relative to the formation, the cutting element 10 is dragged across the surface of the formation and the cutting edge of the cutting surface 16 shears away formation material. Such cutting elements 10 are often referred to as “polycrystalline diamond compact” (PDC) cutting elements, or cutters.
During drilling, cutting elements 10 are subjected to high temperatures due to friction between the diamond table and the formation being cut, high axial loads from weight on the weight on bit (WOB), and high impact forces attributable to variations in WOB, formation irregularities and material differences, and vibration. These conditions can result in damage to the layer of superabrasive material 12 (e.g., chipping, spalling). Such damage often occurs at or near the cutting edge of the cutting surface 16 and is caused, at least in part, by the high impact forces that occur during drilling. Damage to the cutting element 10 results in decreased cutting efficiency of the cutting element 10. In severe cases, the entire layer of superabrasive material 12 may separate (i.e., delaminate) from the supporting substrate 14. Furthermore, damage to the cutting element 10 can eventually result in separation of the cutting element 10 from the surface of the earth-boring tool to which it is secured.